The leaning tower of Pisa?

[xx-teagan-xx]

- Why hasn't it fallen over?- If you were an engineer, what would you do to try to stop the continued leaning?- If you were an engineer, what would you do to try to push the tower back to being straight - without damaging it?

[COWBOY1199]

According to me the surface on which it is made is so much clayey that it is making it lean towards its one side. May be its centre of mass is in such a place that after being leaned so much it hasn't fallen over. It can't be prevented from leaning and to even try such a task would be dangerous for the tower as its walls and base are much older .

[RodMac]

The Tower of Pisa was a work of art, performed in three stages over a period of about 177 years. Construction of the first floor of the white marble campanile began on August 9, 1173, a period of military success and prosperity. This first floor is surrounded by pillars with classical capitals, leaning against blind arches.The tower began to sink after construction progressed to the third floor in 1178. This was due to a mere three-meter foundation, set in weak, unstable subsoil. This means the design was flawed from the beginning. Construction was subsequently halted for almost a century, because the Pisans were almost continually engaged in battles with Genoa, Lucca and Florence. This allowed time for the underlying soil to settle. Otherwise, the tower would almost certainly have toppled. In 1198, clocks were temporarily installed on the third floor of the unfinished construction.In 1272, construction resumed under Giovanni di Simone, architect of the Camposanto. In an effort to compensate for the tilt, the engineers built higher floors with one side taller than the other. This made the tower begin to lean in the other direction. Because of this, the tower is actually curved. Construction was halted again in 1284, when the Pisans were defeated by the Genoans in the Battle of Meloria.The seventh floor was completed in 1319. The bell-chamber was not finally added until 1372. It was built by Tommaso di Andrea Pisano, who succeeded in harmonizing the Gothic elements of the bell-chamber with the Romanesque style of the tower. There are seven bells, one for each note of the musical scale. The largest one was installed in 1655.After a phase (1990-2001) of structural strengthening, the tower is currently undergoing gradual surface restoration, in order to repair visual damage, mostly corrosion and blackening. These are particularly strong due to the tower's age and to its particular conditions with respect to wind and rain.